Ember 在 hasMany 关系上计算属性未更新且在保存时加倍

Question

我有两个模型，一个与另一个有很多关系：

装运：

import DS from 'ember-data';

export default DS.Model.extend({
  pickup_address: DS.belongsTo('address', { inverse: null }),
  delivery_address: DS.belongsTo('address', { inverse: null }),
  shipment_lines: DS.hasMany('shipment-line', { inverse: null }),
  shipmentPrice: Ember.computed('shipment_lines.@each.package_price', function () {
    let price = 0;
    this.get('shipment_lines').forEach(function(shipment_line) {
      price += Number(shipment_line.get('package_price'));
    });
    return price;
  }),
});

以及装运线型号：

import DS from 'ember-data';

export default DS.Model.extend({
    description: DS.attr('string'),
    package_weight: DS.attr('number'),
    package_length: DS.attr('number'),
    package_width: DS.attr('number'),
    package_height: DS.attr('number'),
    package_price: DS.attr('number'),
});

在控制器中，当我向装运添加新装运行时，我从 API 获取包裹价格并将其添加到装运行：

addShipmentLine(shipmentLine) {
  // Get price for shipment line
  this.getShipmentLinePrice(shipmentLine);

  // Add shipment line to shipment
  let shipment = this.get('shipment');
  shipment.get('shipment_lines').addObject(shipmentLine);
},

getShipmentLinePrice 函数（简化）：

getShipmentLinePrice(shipmentLine) {
    ...
    // Get weight and type
    let weight = shipmentLine.get('package_weight');
    let length = shipmentLine.get('package_length');
    let height = shipmentLine.get('package_height');
    let width  = shipmentLine.get('package_width');

    // Fetch price from API
    this.get('price').getPackagePrice(weight, length, height, width).then(
        (price) => {
            shipmentLine.set('package_price', price['price']);
        }
    );
}

最后，当我尝试在模板中打印 shipmentPrice 时，它没有更新。即使价格从服务器返回并且 shipment_lines package_price 已设置。

此外，当我用 shipment.save(); 保存货件并将路线重定向到显示页面时，价格会翻倍，直到我刷新页面。页面刷新后，一切正常显示。

所以第一个问题是，如何在添加新的装运行对象时更新装运计算属性装运价格？还是不可能？

第二个问题，为什么保存后价格会翻倍？

Answer 1

尝试：

shipmentPrice: Ember.computed('shipment_lines.[]', function () {
    let price = 0;
    this.get('shipment_lines').forEach(function(shipment_line) {
       price += Number(shipment_line.get('package_price'));
    });
    return price;
}),

Answer 2

我终于弄明白了。好吧，至少我找到了解决方法。保存模型后，我手动将 shipmentPrice 重置为 0:

freight_order.save().then(
    (new_freight_order) => {
        shipment.set('shipmentPrice', 0);
        this.transitionToRoute('shipments.show', new_freight_order.id);
    }
);

我想服务器响应由于某种原因被添加到计算值中。

Ember 在 hasMany 关系上计算属性未更新且在保存时加倍

Ember Computed Property on hasMany relationship not updating and doubles on save

ember.js

ember-data

ember-cli

Ember 在 hasMany 关系上计算 属性 未更新且在保存时加倍

Ember Computed Property on hasMany relationship not updating and doubles on save

ember.js

ember-data

ember-cli

Ember 在 hasMany 关系上计算属性未更新且在保存时加倍